 # Index To Math Model Symbols

 Symbol Description Orthogonal unit vectors along the axes of the Earth-Centered, Earth-Fixed (ECEF) frame of reference Orthogonal unit vectors along the axes of North-Oriented, Local-Level (NOLL) frame of reference Orthogonal unit vectors along the axes of the Velocity-Oriented (VO) frame of reference Orthogonal unit vectors along the axes of the Body-fixed frame of reference Rotation operator that transforms vectors expressed relative to the North-Oriented, Local-Level (NOLL) frame of reference to equivalent vectors relative to the Earth-Centered, Earth-Fixed (ECEF) frame Rotation operator that transforms vectors expressed relative to the Earth-Centered, Earth-Fixed (ECEF) frame of reference to equivalent vectors relative to the North-Oriented, Local-Level (NOLL) frame Rotation operator that transforms vectors expressed relative to the Velocity-Oriented (VO) frame of reference to equivalent vectors relative to the North-Oriented, Local-Level (NOLL) frame Rotation operator that transforms vectors expressed relative to the North-Oriented, Local-Level (NOLL) frame of reference to equivalent vectors relative to the Velocity (VO) frame Rotation operator that transforms vectors expressed relative to the Body-fixed (BODY) frame of reference to equivalent vectors relative to the Velocity-Oriented (VO) frame Rotation operator that transforms vectors expressed relative to the Velocity-Oriented (VO) frame of reference to equivalent vectors relative to the Body-fixed (BODY) frame Earth rate Aerodynamic lift Commanded lift Aerodynamic drag Engine thrust as a function of time Commanded thrust Total force acting at the aircrafts center of gravity Component of total force parallel to the aircrafts velocity vector Component of total force normal to the aircrafts velocity vector m, m(t) Instantaneous aircraft mass Mass of the fully loaded aircraft Aircraft position at time, t, relative to the Earth-Centered, Earth-Fixed (ECEF) frame h Aircraft altitude Aircraft roll angle Aircraft pitch angle Yaw True aircraft heading Magnetic aircraft heading Desired heading Commanded heading Flight path angle Acceleration due to gravity at a distance, r, from the earths center Flight path angle Commanded flight path angle Desired flight path angle Geodetic Latitude Geodetic Longitude Aircraft's earth relative velocity Commanded speed Desired speed Groundspeed True airspeed Indicated airspeed Mach number T, T(h) Ambient air temperature as a function of altitude, h Static air pressure as a function of altitude, h Stagnation or total air pressure as measured by a Pitot-Static system Air density as a function of altitude, h Air density with corresponding pressure  Speed of sound in air as a function of altitude